Delay-action exploder.



F. BERNARDI 6: J. B. SAUVE.

DELAY ACTION EXPLODER.

APPLICATION FILED 00121, 1911.

Patented June 11, 1912.

situarse aranci onere.;

FRANK BERNARDI AND JOHN B. SAUVE, F MOKEL'UMNE HILL, CALIFORNIA, AS-SIG-NORS TO PATENT ELECTRIC FUSE SPITTER C0., OF MOKELUMNE HILL, CALI-FORNIA, A CORPORATION OF CALIFORNIA.

DELAY-ACTION nxinonnr..-

Specification of Letters Patent..

Patented une ii, MM2.

Applicbtion filed October 21, 1911. Serial No. 655,875;

and Jol-IN B. SAUvE, both citizens of the United States, residing atMokelumne Hill, in the county of Calaveras and State of California, haveinvented new and useful Improvements in Delay-Action E'xploders, owhichthe following is a specilication.

This invention relates to a delay act-ion exploder or time fuse, such asisV employed in blasting operations.

It is the object of this invention to provide a delay action exploder ortime fuse which is so constructed that it will explode to set 0H ablasting charge at a time subsequent to the moment of ignition of thefuse; in which the length or lapse of time between the moment ofignition and the moment of explosion is governed by the lengt-h of thefuse; and which is so arranged as to be ignited by the' action of anelectric current.

Delay action exploders or fuses of the above character are employed inmining and blasting operations, and are usually arranged in series invariously positioned charges 0r blasts, and are connected to anelectrical conductor, through which a current is sent to light the fusesin the se'ries simultaneously. The fuses are of various lengths ortimes, when it is desired that they explode successively to set 0E thecharges at suitable intervals, and are equally timed when they are toexplode simultaneously; in either event the explosion taking place sometime after the ignition of the fuse. Great trouble has been experiencedin the use of electrically ignited time fuses, by reason of prematureexplosions or burning of the blasting charge, occasioned by backring ofthe fuse into the explosive material in which-it is embedded.

It is the purpose of this invention to obviate this trouble, which isaccomplished by so constructing the ignition end of the fuse that theiames or sparks emitted by the burning fuse will not come into contactwith the explosive charge, but which will permit of the escape of thegases ,or products of combustion arising from the burning fuse so as toinsure an even lire.

Other objects will become apparent hereinafter.

The invention consists of the parts and the construction and combinationof parts,

`as hereinafter more fully described and claimed, having reference tothe accompanying drawings, in which- -Figure l is a vertical section ofthe invention. Fig. 2 is an enlarged end view of same. Figs. 3,4, and 5are details showing modified forms of the flame filter.

In the drawings, A represents a cylindrical fuse, consisting of woundlayers.of tape or the like, formed with a perforation extendinglongitudinally therethrough, which perforation-is designed to be filledwith meal powder or the like, indicated at 2. Ametallic sheath?) iscrimped or otherwise secured to one end of the fuse A and forms areceptacle for an explosive substance 4, such as fulminate of mercury orthe like, forming a cap, by the explosion of which the actual explosionof the blastingcharge is edected; the explosive t being preferably insolid form and'spaced a short distance from the end Of the powder core 2to form an air space 4. Theend of the fuse is cut at an angle, so that.when it is inserted in the sheath 3, its long edge will contact theexplosive 4, as

shown, so as to form the air space 4, the

provision of which insures the ignition and explosion of the explosive4. The other' end of the fuse is fitted with ametal ferrule 5 which issecured to the fuse so as to form a Ywatertight joint by crimping orotherwise.

The ferrule 5 extends some distance beyond the end of the fuse and isslightly enlargei. beyond the point of juncture with the fuse to form ashoulder 6, and at the same time increase its capacity. The end of thefuse A within the ferr-111e 5 is split a short distance to form a pocketor recess for the reception of a small quantity of quick fire powder, asindicated at 7 this `quick tire powder contacting or forming part of thepowder core 2 in the fuse and extending over the upper end of the fuse.The purposeA of this pocket of quick tire powder at this point isto'insure the ignition of the core 2 when thej fuse is lighted, as willpresently be described.

-ferrule 5 adjacent the quick lire powder on the end of the fuse, assh'own at 8, with which a small quantity of the quick fire powder ismingled.

A air of insulated electrical conductors 9-9 of any suitable length ismounted in a plug 10 formed of sulfur or similar material, and extendingtherethrough' a short distance, are' connected together by means.

of a platinum wire or bridge 9', which, when the plug 10 is inserted inthe ferrule 5, as shown, will be embedded in the guncotton 8. The plug10 is formed with a central perforation 11 of small diameter, which isclosed by means of a shot or wad 12 at its upper end to form an airspace in the perforation adjacent-to the guncotton; the air contained inthis space facilitating the ignition and explosion of the guncotton.

A sulfur plug 13 is formed in the outer end of the ferrule so as toembed a section of the conductors 9, the plug 13 being formed by pouringmolten sulfur into the open end of the ferrule around a central core.Annular grooves 14 are formed in the ferrule, into which the moltensulfur will run and when the latter hardens, prevent the plug thusformed from working or falling out of the ferrule. The central corebeing removed, a perforation 15 is formed, which perforation extendslongitudinally through the plug 13 centrally thereof and communicateswith, and is larger in diameter than, thc perforation 11 in the plug 10,so that a seat will be formed for the shot or wad 12, which is thendropped into position through the perforation 15.

A soft wax or grease plug 16 is formed in the perforation 15 by pouringa suitable wax, grease, or composition into the outer open end thereof,which plug is designed to form a ,water and air-tight seal above theshot or wad 12; the latter acting to prevent the wax from coming incontact with the guncotton 8. The end of the sulfur plug 13 is coveredwith the wax 16, as is the Joint between the plug and the ferrule 5, soas to form a waterproof seal at this point. A

Mounted on the outer end of the ferrule 5 is a hood or dome 17, which isprovided on its end portion with a series of small holes or perorations18. The end portion ofthe dome 17 is spaced some distance from the endof the ferrule 5 and plug 13 and is designed to contain a small quantityof asbestos fiber 19 or a like material which is suliciently loose topermit of the passage of air therethrough, but of such compactness as toprevent iames from passing through the perforations 18 when the fuse 1signited. as will be later described. A line wire screen or gauze 20 maybe employed in lieu of the asbestos fiber, if desired, as shown in Fig.3, or maybe used in conjunction therewith, `as shown in Fig. 4.

The electrical conductors 9--9 pass through the dome 17 and are adaptedto be connected at their outer ends to any suitable lsource ofelectrical supply which may be regulated and controlled in any suitablemanner.

The fuse A is inclosed in a casing 20 which extends over the sheath 3and 1s attached at its upper end to the ferrule 5 adjacent to theshoulder. The casing 20 may be formed of any suitable material, in someinstances metal tubing being employed, whereas in other cases'a rubbertube 'is used which is dipped in paraffin or other wax to render itimpervious to water. The casing 20 together with the wax plug 16 act to'prevent moisture from reaching the fuse when it is submerged in water,as is frequently the case in mine work.

In the application of this invention, the device composed of the partsenumerated, is placed in the charge of explosive, such as dynamite ornitro-glycerin, to be exploded, and the wires 9 9 are attached toasuitable source of electric supply. An electric current being caused toiow through the conductors 9 9, heats the vplatinum wire or filament 9to such an extent that the guncotton 8 will be ignited and exploded,which acts to set fire to the meal powder 7 on the end of the powdercore 2, so as to light the latter, and at the same time blows the shotor wad 12, together with the wax plug 16,

out of the longitudinal bore 15 ofthe plug y 13 into the space withinthe hood 17 between the endof the plug 13 and the asbestos screen 19.-The opening of the bore 15 lforms a vent for the gases formed by theburning core 2, which gases pass through the asbestos screen 19 and theperforated i hood 17; the screen acting to preventthe escape of thedames or sparks which are confined within the hood. This prevents theignition of the explosive material in which the exploder isembeddedandvis particularly advantageous where black powder is being used.Vhenthe core 2 has burned to the explosive materials et in the sheath 3,these materials are ignited and caused to explode so as to set off theexplosive in which the exploder is placed. In the event black powder orother explosive adapted to explode by the action of a flame instead ofpercussion, is used, the cap composed of the sheath 3 and explosive 4may be dispensed with.

From the foregoing it will be seen that we have produced a delay actionexploder which is simple in construction, efcient, safe and reliable.

If desired,perforations 21 may be formed in the ferrule 5, as shown inFig. 5, adjacent the space occupied by the guncotton 8, and a hood 17having perforations 18 and containing loose asbestos 19 or other screen,placed over the -perforations21. The rubber jacket 20 is carried overthe perforations 21 to exclude moisture; this rubber blowing away whenthe guncotton 8 is exploded, as before described. In this case the gaseswill escape through the filter or screen 19 out the perforations 18.This arrangement may be employed in conjunction with the hood 17, or thelatter may be dispensed with if desired.

Having thus described our invention, what we claim and desire to secureby Letters Patent is-.

1. The combination withv a fuse, of a female member thereon having achamber to contain an inflammable substance, said chamber having a ventfor the gases generated by the ignition of said substance, electricalmeans for firing said substance, and a perforated cap inclosing achamber into which the vented gases from the firstnamed chamber exhaustbefore being released to the atmosphere, to prevent premature explosion.

2. The combination with a fuse, of a female member thereon, having achamber to contain an infiammable substance, said chamberhavinga"'ventforthe gases generated by the ignition of said substance,electrical means for firing said substance, aV perforated cap inclosinga chamber into which the vented gases from the first-named chamberexhaust beforeV being released to the atmosphere, to prevent prematureexplosion, and a reproof filtering material in said cap.

3. A delay action exploder comprising a fuse, a ferrule attached to oneend o f the fuse, an explosive in the ferrule adjacent to the fuse, afilament embedded-in the explosive, an electrical conductor attached toeach end of the filament, a plug in which the conductors are mountedarranged in the ferrule adjacent to the explosive, a perforation in saidplug extending lengthwise and centrally thereof, to form an air space,an auxiliary plug formed in the outer end of the ferrule for holding thefirst named plug in position, a perforation extending lengthwise throughsaid plug registering with the perforation in the first named plug, awad for closing the first named perforation, and a grease filling in thelast named perforation above the wad.

4. A delay action exploder comprising a fuse, a ferrule attached to oneend of the fuse, an explosive in the ferrule adjacent to the fuse, afilament embedded in the explosive, an electrical conductor attached toeach end of the filament, a vplug in which the conductors are mountedarranged in the ferrule adjacent to the explosive, a perforation in saidplug extending lengthwise and centrally thereof, to form an air space,an aux- `fuse, a filament embedded in the explosive,

an electrical conductor attached to each end of the filament, a plug inwhich the conductors are mounted arranged in the ferrule adjacent to theexplosive, a perforation in said plug extending lengthwise and centrallythereof, to form an air space, an auxiliary plug formed in the outer endof the ferrule for holding the first named plug in position, aperforation extending lengthwise through said plug registering with theperforation in the first named plug, a wad for closing the first namedperforation, a grease filling in the last named perforation above thewad, means formed inA the ferrule for i'etaining the last named plugtherein, a perforatedA dome mounted on the end of the'ferrle','^and afiaine filter in said dome.

6. A delay action exploder comprising a fuse, a ferrule attached to oneend of the fuse, an explosive in the ferrule adjacent to the fuse, afilament embedded in the explosive, an electrical conductor attached toeach end of the filament, a plug in which the conductors are mountedarranged in the ferrule adjacent to the explosive, a perforation in saidplug extending lengthwise and centrally thereof, to form an air space,an auxiliary plug formed in the outer end o-f the ferrule for holdingthe first named plug in position, a perforation extending lengthwisethrough said plug registering with the perforation in the first namedplug, a wad for closing the first named perforation, a grease filling inthe last named perforation above the wad, means formed in the ferrulefor retaining the last named plug therein, a perforated dome mounted onthe end of the ferrule, a fiame filter in said dome, and an explosivecap mounted on the other end of the fuse with an air space therebetween.

7 The combination with a fuse having an electric igniter, and means forventing the gases generated by the burning fuse, of an external ventedhood for confining the sparks and flames occasioned by the ignition ofthe fuse to prevent baekfiring.

8. The combination with a fuse having electric igniter, and means forVenting the gases generated by -the burning fuse, of Vmeans for connngthe sparks and ames foccasoned by the ignition of the fuse to preventbackring, comprising a perforate (onle arranged over the vent7 'and aflame hlter m the dome.

In testimony whereof We have hereunto set our hands in the presence oftwo sub- 10 scribing Witnesses.

FRANK BERNARDI. A JOHN B. SAUVE. Witnesses FRANK J. SEIBEL, CHARLES P.VICINI.

